text: /* @(#)xdr.h	2.2 88/07/29 4.0 RPCSRC */
  /*
   * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   * unrestricted use provided that this legend is included on all tape
   * media and as a part of the software program in whole or part.  Users
   * may copy or modify Sun RPC without charge, but are not authorized
   * to license or distribute it to anyone else except as part of a product or
   * program developed by the user.
   * 
   * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
   * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
   * 
   * Sun RPC is provided with no support and without any obligation on the
   * part of Sun Microsystems, Inc. to assist in its use, correction,
   * modification or enhancement.
   * 
   * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
   * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
   * OR ANY PART THEREOF.
   * 
   * In no event will Sun Microsystems, Inc. be liable for any lost revenue
   * or profits or other special, indirect and consequential damages, even if
   * Sun has been advised of the possibility of such damages.
   * 
   * Sun Microsystems, Inc.
   * 2550 Garcia Avenue
   * Mountain View, California  94043
   */
  /*      @(#)xdr.h 1.19 87/04/22 SMI      */
  
  /*
   * xdr.h, External Data Representation Serialization Routines.
   *
   * Copyright (C) 1984, Sun Microsystems, Inc.
   */
  
  #ifndef GSSRPC_XDR_H
  #define GSSRPC_XDR_H
  
  #include <stdio.h>		/* for FILE */
  
  GSSRPC__BEGIN_DECLS
  /*
   * XDR provides a conventional way for converting between C data
   * types and an external bit-string representation.  Library supplied
   * routines provide for the conversion on built-in C data types.  These
   * routines and utility routines defined here are used to help implement
   * a type encode/decode routine for each user-defined type.
   *
   * Each data type provides a single procedure which takes two arguments:
   *
   *	bool_t
   *	xdrproc(xdrs, argresp)
   *		XDR *xdrs;
   *		<type> *argresp;
   *
   * xdrs is an instance of a XDR handle, to which or from which the data
   * type is to be converted.  argresp is a pointer to the structure to be
   * converted.  The XDR handle contains an operation field which indicates
   * which of the operations (ENCODE, DECODE * or FREE) is to be performed.
   *
   * XDR_DECODE may allocate space if the pointer argresp is null.  This
   * data can be freed with the XDR_FREE operation.
   *
   * We write only one procedure per data type to make it easy
   * to keep the encode and decode procedures for a data type consistent.
   * In many cases the same code performs all operations on a user defined type,
   * because all the hard work is done in the component type routines.
   * decode as a series of calls on the nested data types.
   */
  
  /*
   * Xdr operations.  XDR_ENCODE causes the type to be encoded into the
   * stream.  XDR_DECODE causes the type to be extracted from the stream.
   * XDR_FREE can be used to release the space allocated by an XDR_DECODE
   * request.
   */
  enum xdr_op {
  	XDR_ENCODE=0,
  	XDR_DECODE=1,
  	XDR_FREE=2
  };
  
  /*
   * This is the number of bytes per unit of external data.
   */
  #define BYTES_PER_XDR_UNIT	(4)
  #define RNDUP(x)  ((((x) + BYTES_PER_XDR_UNIT - 1) / BYTES_PER_XDR_UNIT) \
  		    * BYTES_PER_XDR_UNIT)
  
  /*
   * A xdrproc_t exists for each data type which is to be encoded or decoded.
   *
   * The second argument to the xdrproc_t is a pointer to an opaque pointer.
   * The opaque pointer generally points to a structure of the data type
   * to be decoded.  If this pointer is 0, then the type routines should
   * allocate dynamic storage of the appropriate size and return it.
   * bool_t	(*xdrproc_t)(XDR *, caddr_t *);
   *
   * XXX can't actually prototype it, because some take three args!!!
   */
  typedef	bool_t (*xdrproc_t)();
  
  /*
   * The XDR handle.
   * Contains operation which is being applied to the stream,
   * an operations vector for the paticular implementation (e.g. see xdr_mem.c),
   * and two private fields for the use of the particular impelementation.
   */
  typedef struct XDR {
  	enum xdr_op	x_op;		/* operation; fast additional param */
  	struct xdr_ops {
  		/* get a long from underlying stream */
  		bool_t	(*x_getlong)(struct XDR *, long *);
  
  		/* put a long to underlying stream */
  		bool_t	(*x_putlong)(struct XDR *, long *);
  
  		/* get some bytes from underlying stream */
  		bool_t	(*x_getbytes)(struct XDR *, caddr_t, u_int);
  
  		/* put some bytes to underlying stream */
  		bool_t	(*x_putbytes)(struct XDR *, caddr_t, u_int);
  
  		/* returns bytes off from beginning */
  		u_int	(*x_getpostn)(struct XDR *);
  
  		/* lets you reposition the stream */
  		bool_t	(*x_setpostn)(struct XDR *, u_int);
  
  		/* buf quick ptr to buffered data */
  		rpc_inline_t *(*x_inline)(struct XDR *, int);
  
  		/* free privates of this xdr_stream */
  		void	(*x_destroy)(struct XDR *);
  	} *x_ops;
  	caddr_t 	x_public;	/* users' data */
  	void *		x_private;	/* pointer to private data */
  	caddr_t 	x_base;		/* private used for position info */
  	int		x_handy;	/* extra private word */
  } XDR;
  
  /*
   * Operations defined on a XDR handle
   *
   * XDR		*xdrs;
   * int32_t	*longp;
   * caddr_t	 addr;
   * u_int	 len;
   * u_int	 pos;
   */
  #define XDR_GETLONG(xdrs, longp)			\
  	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)
  #define xdr_getlong(xdrs, longp)			\
  	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)
  
  #define XDR_PUTLONG(xdrs, longp)			\
  	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)
  #define xdr_putlong(xdrs, longp)			\
  	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)
  
  #define XDR_GETBYTES(xdrs, addr, len)			\
  	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
  #define xdr_getbytes(xdrs, addr, len)			\
  	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
  
  #define XDR_PUTBYTES(xdrs, addr, len)			\
  	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
  #define xdr_putbytes(xdrs, addr, len)			\
  	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
  
  #define XDR_GETPOS(xdrs)				\
  	(*(xdrs)->x_ops->x_getpostn)(xdrs)
  #define xdr_getpos(xdrs)				\
  	(*(xdrs)->x_ops->x_getpostn)(xdrs)
  
  #define XDR_SETPOS(xdrs, pos)				\
  	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
  #define xdr_setpos(xdrs, pos)				\
  	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
  
  #define	XDR_INLINE(xdrs, len)				\
  	(*(xdrs)->x_ops->x_inline)(xdrs, len)
  #define	xdr_inline(xdrs, len)				\
  	(*(xdrs)->x_ops->x_inline)(xdrs, len)
  
  #define	XDR_DESTROY(xdrs)				\
  	if ((xdrs)->x_ops->x_destroy) 			\
  		(*(xdrs)->x_ops->x_destroy)(xdrs)
  #define	xdr_destroy(xdrs)				\
  	if ((xdrs)->x_ops->x_destroy) 			\
  		(*(xdrs)->x_ops->x_destroy)(xdrs)
  
  /*
   * Support struct for discriminated unions.
   * You create an array of xdrdiscrim structures, terminated with
   * a entry with a null procedure pointer.  The xdr_union routine gets
   * the discriminant value and then searches the array of structures
   * for a matching value.  If a match is found the associated xdr routine
   * is called to handle that part of the union.  If there is
   * no match, then a default routine may be called.
   * If there is no match and no default routine it is an error.
   */
  #define NULL_xdrproc_t ((xdrproc_t)0)
  struct xdr_discrim {
  	int	value;
  	xdrproc_t proc;
  };
  
  /*
   * In-line routines for fast encode/decode of primitve data types.
   * Caveat emptor: these use single memory cycles to get the
   * data from the underlying buffer, and will fail to operate
   * properly if the data is not aligned.  The standard way to use these
   * is to say:
   *	if ((buf = XDR_INLINE(xdrs, count)) == NULL)
   *		return (FALSE);
   *	<<< macro calls >>>
   * where ``count'' is the number of bytes of data occupied
   * by the primitive data types.
   *
   * N.B. and frozen for all time: each data type here uses 4 bytes
   * of external representation.
   */
  #define IXDR_GET_INT32(buf)		((int32_t)IXDR_GET_U_INT32(buf))
  #define IXDR_PUT_INT32(buf, v)		IXDR_PUT_U_INT32((buf),((uint32_t)(v)))
  #define IXDR_GET_U_INT32(buf)		(ntohl((uint32_t)*(buf)++))
  #define IXDR_PUT_U_INT32(buf, v)	(*(buf)++ = (int32_t)htonl((v)))
  
  #define IXDR_GET_LONG(buf)		((long)IXDR_GET_INT32(buf))
  #define IXDR_PUT_LONG(buf, v)		IXDR_PUT_U_INT32((buf),((uint32_t)(v)))
  
  #define IXDR_GET_BOOL(buf)		((bool_t)IXDR_GET_LONG(buf))
  #define IXDR_GET_ENUM(buf, t)		((t)IXDR_GET_INT32(buf))
  #define IXDR_GET_U_LONG(buf)		((u_long)IXDR_GET_U_INT32(buf))
  #define IXDR_GET_SHORT(buf)		((short)IXDR_GET_INT32(buf))
  #define IXDR_GET_U_SHORT(buf)		((u_short)IXDR_GET_U_INT32(buf))
  
  #define IXDR_PUT_BOOL(buf, v)		IXDR_PUT_INT32((buf),((int32_t)(v)))
  #define IXDR_PUT_ENUM(buf, v)		IXDR_PUT_INT32((buf),((int32_t)(v)))
  #define IXDR_PUT_U_LONG(buf, v)		IXDR_PUT_U_INT32((buf),((uint32_t)(v)))
  #define IXDR_PUT_SHORT(buf, v)		IXDR_PUT_INT32((buf),((int32_t)(v)))
  #define IXDR_PUT_U_SHORT(buf, v)	IXDR_PUT_U_INT32((buf),((uint32_t)(v)))
  
  /*
   * These are the "generic" xdr routines.
   */
  extern bool_t	xdr_void(XDR *, void *);
  extern bool_t	xdr_int(XDR *, int *);
  extern bool_t	xdr_u_int(XDR *, u_int *);
  extern bool_t	xdr_long(XDR *, long *);
  extern bool_t	xdr_u_long(XDR *, u_long *);
  extern bool_t	xdr_short(XDR *, short *);
  extern bool_t	xdr_u_short(XDR *, u_short *);
  extern bool_t	xdr_bool(XDR *, bool_t *);
  extern bool_t	xdr_enum(XDR *, enum_t *);
  extern bool_t	xdr_array(XDR *, caddr_t *, u_int *,
  			u_int, u_int, xdrproc_t);
  extern bool_t	xdr_bytes(XDR *, char **, u_int *, u_int);
  extern bool_t	xdr_opaque(XDR *, caddr_t, u_int);
  extern bool_t	xdr_string(XDR *, char **, u_int);
  extern bool_t	xdr_union(XDR *, enum_t *, char *, struct xdr_discrim *,
  			xdrproc_t);
  extern bool_t	xdr_char(XDR *, char *);
  extern bool_t	xdr_u_char(XDR *, u_char *);
  extern bool_t	xdr_vector(XDR *, char *, u_int, u_int, xdrproc_t);
  extern bool_t	xdr_float(XDR *, float *);
  extern bool_t	xdr_double(XDR *, double *);
  extern bool_t	xdr_reference(XDR *, caddr_t *, u_int, xdrproc_t);
  extern bool_t	xdr_pointer(XDR *, char **, u_int, xdrproc_t);
  extern bool_t	xdr_wrapstring(XDR *, char **);
  
  extern unsigned long xdr_sizeof(xdrproc_t, void *);
  
  #define xdr_rpcprog	xdr_u_int32
  #define xdr_rpcvers	xdr_u_int32
  #define xdr_rpcprot	xdr_u_int32
  #define xdr_rpcproc	xdr_u_int32
  #define xdr_rpcport	xdr_u_int32
  
  /*
   * Common opaque bytes objects used by many rpc protocols;
   * declared here due to commonality.
   */
  #define MAX_NETOBJ_SZ 2048
  struct netobj {
  	u_int	n_len;
  	char	*n_bytes;
  };
  typedef struct netobj netobj;
  
  extern bool_t   xdr_netobj(XDR *, struct netobj *);
  
  extern bool_t	xdr_int32(XDR *, int32_t *);
  extern bool_t	xdr_u_int32(XDR *, uint32_t *);
  
  /*
   * These are the public routines for the various implementations of
   * xdr streams.
   */
  
  /* XDR allocating memory buffer */
  extern void	xdralloc_create(XDR *, enum xdr_op);
  
  /* destroy xdralloc, save buf */
  extern void	xdralloc_release(XDR *);
  
  /* get buffer from xdralloc */
  extern caddr_t	xdralloc_getdata(XDR *);
  
  /* XDR using memory buffers */
  extern void	xdrmem_create(XDR *, caddr_t, u_int, enum xdr_op);
  
  /* XDR using stdio library */
  extern void	xdrstdio_create(XDR *, FILE *, enum xdr_op);
  
  /* XDR pseudo records for tcp */
  extern void	xdrrec_create(XDR *xdrs, u_int, u_int, caddr_t,
  			int (*) (caddr_t, caddr_t, int),
  			int (*) (caddr_t, caddr_t, int));
  
  /* make end of xdr record */
  extern bool_t	xdrrec_endofrecord(XDR *, bool_t);
  
  /* move to beginning of next record */
  extern bool_t	xdrrec_skiprecord (XDR *xdrs);
  
  /* true if no more input */
  extern bool_t	xdrrec_eof (XDR *xdrs);
  
  /* free memory buffers for xdr */
  extern void	xdr_free (xdrproc_t, void *);
  GSSRPC__END_DECLS
  
  #endif /* !defined(GSSRPC_XDR_H) */
  